Filtering system, device used therein, and method of filtration



0aw 15,1940. 'W.C.LAUGHLIN 2,217,689

FILTERING SYSTEM, DEVICE USED THEREIN, AND METHOD OF FILTRATION Filed July 17, 1957 7 Sheets-Sheet l g' llill v Oct. 15, 1940. w. LAUGHLXN I 2,217,689

FILTERING SYSTEM, DEVICE ussn THEREIN, AND METHOD OF FILTRATION Filed July 17, 1957 7 Sheets-Sheet 2 7y IHHII 'HHII BY .7 ATT E.

Oct. 15, 1940. w. c. LAUGHLIN, 2,217,689 I FILTERING SYSTEM, DEVICE USED THEREIN, AND METHOD 0F FILTRATION Filed July 17, 1937 V 7 Sheets-Shet z W .T M Mb y W Oct. 15, 1940. 2,217,689 FILTERING SYSTEM, DEVICE USED THEREIN, AND METHOD OF FILTRATION w. c. LAUGHLIN 7 Sheets-Sheet 4 Filed July 17, 1957 Q NE Oct. 15, 1940' w. LAUGHLINV' 2,217,639

FILTERING SYSTEM, DEVICE USED THEREIN, ANDMETHOD 'OF FILTRATION Filed July 17, 19s? I 7 Sheets-Sheet 5 INVENTOR. [WW/2m; C lazy/M71 Oct. 15, 1940. w c. LAUGHLIN 1 ,21

FILTERING SYSTEM; DEVICE USED THEREIN, AND METHOD OF FILTRATION Filed July 17, 1937 7 Sheets-Sheet s Oct. 15, 1940. w c. LAUGHLIN FILTERING SYSTEM, DEVICE USED THEREIN, AND METHOD OF FILTRATION '7 Sheets-Sheet 7 Filed July 17, 1957 R W 2, M mw VZ w A W .0

Patented Oct. 15, 1940 m'rnnnvc 'sr'srnlu', DEVICE nsnn THERE'- N, AND lun'rrlon or FILTRATION William C. Ianghlin', New York, N. Y assi'gnor,

by mesne assignmen poration, Dover, Delaware,

Delaware tato-w. C. Langhlin Oora corporation .of-

Application July 1'1, 1937; Serial No. 154.226 1.; Claims; (01. 210-428) This invention relates to filtrationjsystem's used in connection with the clarification of waters.

sewage. industrial waste waters, etc., and has for its object to provide an improved system overcoming the objections to those heretofore proposed. My improved system of filtration consists in subjecting a filter bed to a surface cleaning at periodic times, and to a deep cleaning at other times,

the former depending on time intervalsfandthe latter on head controLthe injection of water with orwithout air being used in connection'with such deep cleaning.

The invention consists further in 'the novel "de vices employed in carrying out theimproved sys l5 tem, first, in the provision of an improved surface cleaning which consists in means riding along -the surface of the filter bed, means for removing-impurities from the surface layer of 'the fllter bed, means for removing the impure water, and means for returning any part of the 'filter bed removed therefrom by the operation of the device. .'This surface cleaning is carried out at we constituents; means being provided to'draw off by siphoning action the water containingthe impurities. In connection therewith, sand replenishing means are provided to compensate for any sand loss entrained with such impurities.

The invention consists further in means providing for the ready removal of the deep cleaning device, and its replacement under the same ad- Justment conditions.

The invention consists further in providing a pipe having perforations, at the lower part of the filter bed to loosen the material of the filter bed for permitting the descent of a deep cleaner therethrough.

The invention consists still further in improved methods of cleaning filter beds, which consist in 55 tatlon action simul aneously with impingement air so as to remove all impurities of the filter bed upon the constituents of the filter bed of cleaning water, preferably with air, and removing the impurities from the filter bed.

A further method is the replenishment of the filter bed by a supply of filter bed material as re- 5 quired, to supl lyfliter bed material to the filter bed so -as to keep it at a constant level, in the event there has been any loss due to wear or entrainment with the wash water.

"'Ihesemethods consist further in the steps of 1 subjecting the filter bed periodically to the surface cleaning action, and periodically to the deep cleaning action.

' The invention willbe further described hereinafter, embodiments thereof will be shown in the drawings, and theinvention will be finally pointed out in the appended claims.

In the accompanying drawings:

Figure l is a side view of my improved filtration installation showing a broken-away portion to indicate that the filtration tank may be of any length; I

Figure 2 is a horizontal section taken on line 2-2 of Figure 1;

Figure'3 is-a vertical transverse section taken on line 3-4 of Figure l and showing a side view of the surface cleaner in its relation to the filter bed;

Figure 4 is a vertical transverse section taken on line 4-4 of Figure 3 showing the improved so device used for surface cleaning;

Figure 5 is a sectionalview taken on line 5-5 of Figure 3 showing the valve which is operated at each end of the run of the surface cleaner;

Figure 6 is a vertical transverse section taken on line 6-6 of Figure 1;

Figure I is a vertical section taken on line 1-4 of Figure 6;

Figures 8, 9 and 10 show diagrammatically the operation of the device, Figure 8 showing the sur face cleaning action, Figure 9 the deep cleaning step, and Figure 10 the removal of the water with the impurities after the deep cleaner in Figure 9 has churned up" the filter bed, these views in Figures 8, 9and 10 being in transverse sections of the installation. V

Figure 11 is a plan view of the frame taken on line- I l-il oLFigure 6, which in its adjusted position-can be removed and replaced in position, in the event the deep cleaner is taken out for repair or for any other purpose.

Figure 12 is a diagrammatic side view of the filtrate and wash water pipes, shown as determining different levels than .when in the position shown in Figure 1; and 5s Figure 13 is a diagrammatic view of the action of the deep cleaner.

Similar characters of reference indicate corresponding parts throughout the various views.

Referring to the drawings, and more particularly to Figures 8 to 10, the installation there shown consists of a foundation portion II having a launder l2 at'the left hand thereof, and a launder I3 at the right hand thereof. Intermediate of these two launders is a filter bed portion I4 in which the filter bed proper, I5, is supported by a screen I6 placed upon the abutments IT. The central portion I4 is supplied with the water to be filtered through a main supply pipe I8 having branch supply pipes I9 distributed along the length of the central portion I. The

outlet portion of these supply pipes I8 are these, drawings,

shown in Figures 8 to 10, and in the remaining figures they are shown as level with the level line of the water in the central portion I4, this level line being indicated by the character 20a. The level of the water in the launder I2, and the level of the water in the launder I3, is indicated by the characters I21: and I3a. These levels 200, I2a and I3a are shown in all of the drawings as indicative of, the particular installation shown in but they may be varied, as will be hereinafter more fully seen. It is desirable to raise the outlet ends 20 of the branch pipes I9 to as high a point in the central portion I4 as possible, though thatpart does not necessarily determine the level .inthe filter bed channel. The levels I-Ia and I3a are controlled by the position-of outletpipes which are in connection with the launders I2 and,.l3, and which outlet pipes have pipes at right angles to the outlet pipes, the pivotal position of these pivoted pipes enabling the levels In and 13a to be determined. The outlet pipe for the fiiterate in launder I2 is best shown in Figure 2, and is indicated by 2I; and the outlet pipe for the wash water of launder I3 is indicated by 22 in Figure 2. In Figure 12, these outlet pipes are shown diagrammatically in another position which, in consequence, determine other levels.

To the end of pipe 2| there is pivoted a short pipe 23 having an outlet portion 24. This pipe 23 is capable of being moved on its pivotal portion 25 from its horizontal position to a vertical position, and the height of the orifice or outlet 24 of pipe 23 determines the level I2a of the filtrate in the launder I2.

To the outlet pipe 22 a similar short pipe 28 is pivoted, which is shown in dotted lines in Figure l, and its orifice 21 may be moved from its lowermost to the highest position. in a manner similar to the action of the pipe 23, and the position of the orifice 24 determines the level I3a of the wash water in launder I3.

Referring again to Figure 8, there is arranged below the filter bed I5 an enlarged channel 30 through which the filtrate passes and escapes through pipes 3| into the launder I2. with a construction as just described in connection with Figure 8, my improved surface cleaner, indicated in generalby the character 32, is placed upon the top surface of the filter bed I! and moved longitudinally along the same, and as the cleaning action of the surface of the filter bed takes place due to the operation of this surface cleaner 32, the water with impurities is siphoned up through the pipe 33 and discharged at the outlet orifice 34 arranged below the level I3a inthe launder I3. The movement of this water with impurities is indicated by the small arrows,

whereas the movement of the body of the water that is being filtered as it passes through the filter bed proper, enlarged channel 30, pipe 3|, into the launder I2, is indicated by the larger or tailed arrows.

It will be seenirom Figure 8 that the operation there shown is for the purpose of subjecting the topmost layer of the filter bed proper to a surface cleaning action whereby the accumulated impurities upon the filter bed proper are removed. Such impurities are algae, amorphous matter, etc. The to and fro movement of the surface cleaner- 32 brings about this surface cleaning actionof the filter bed. This longitudinal movement of the surface cleaner is carried out periodically in predetermined time intervals by a motor operated travelling carriage.

In certain cases, however, it is desirable to subject the filter bed itself to athorough cleaning. For this purpose, there isshown in Figure 9 the deep cleaner indicated in general by 33, which in passing longitudinally through the filter bed from one end of its length to the other. plows, so to say, the entire contents of the filter bed, and by this plowing action; all the loosened particles of foreign matter adhering to the constituents of the filter bed are removed therefrom by the'action of 'water, or waterand air,.the air being preferably in aspirated form, acting. in the form of a series of jets againstthe constit uents of the filter bed so as to loosen all of the adhering particles. a

As seen from Figure 9, there extends into the riltrate launder. I2 a vertical pipe. 3 6, into which there is suckedby a pump 31 apart of the filtrate in the launder I2, and-this cleanwater or filtrate is forced, .as indicated by the arrows, into the two branch pipes 38. Each of these branch pipes 38 has an air inlet'pipe 38, and

the movement of the water through the depending pipes 40 sucks in a certain amount of air which mixes with the water and is then ejected out of the deep cleaner 35. This water, with or without air, subjects the filter bed to a thorough upwardly-moving cleaning action.

.Should any sand or the like, constituting the filter bed, be drawn up with the water containing the impurities, a provision is made for the replenishing of sand to thefilter bed by means of a sandbox containing sand-46b. as shown in Figure 10., This sandbox 46, in passing over the filter bed I5, always maintains the filter bed at a constant level, since sand passes through the openings. 46a of the sandbox when the level of the filter bed is below the bottom surface of the sandbox. (See Figure l.)

The action of removing the wash water with the impurities stirred up by the deep cleaner 35, takes place simultaneously with the chuming up of the filter bed by means of the device 35, and for-this purpose the removal device 42 shown in Figure 10 is provided. This device 42 is placed above the deep cleaner 35, as shown in Figure 7,.and these in turn are adjacent the sandbox, as shown in Figures 1 and 2, but for clarity in respect to their operations, are shown diagrammatically in separate figures. namely, Figures 9 and 10.

While the ploying action takes place, together 7 with the impingement of the water and air jets, if used, upon the constituents of the filter bed in a relatively localized manner, the churned up and rather ebullient water is captured by an enclosing casing having an open bottom. as shown I in Figure 6. This water containing the impurities is then, by a siphoning action acting upon the removing device 42, shown .in Figure 10, drawn through openings 43 of the removing device 42, and, as shown by the arrows, is siphoned upwardly through the pipe 44 which has its. discharge oriiice 45 in the launder i3 ;below .the water level l3a, as shown-in Figure 10.

From the foregoing, it will have been seen that if only a surface cleaning is desired, the device 32 .is moved periodically longitudinally along. the top surface of thefilter bed, inaccordance with a predetermined time element. .Shouldit be desired to subject the entire filter bed to a thorough cleaning, then the deep cleaning device 35, with the wash water removing device, .endsand replenishing device 46.- .is set into ,operation, whichmay be done also periodically, but preferably dependent upon a predetermined head 0 the right hand side of these figures the deep.

cleaning device .is shown. While these figures only show one surface cleaning device and one deep cleaning device, it is, of course, clear that one deep cleaning device can be usedwith-two surface cleaning-devices, the deep cleaning. device in this case being intermediate of the -.two surface cleaners. -5

Referring now to the left hand portions only of Figures -land 2 and to Figures 3, .4 and 5, the surface cleaning device will be described.

In Figure -4,- the level of the filter bed-J5 is indicated by the surface lia. Along this surface there is passed a surface cleaner indicated-in general by, 32, which consists of .a suspended shoe to having tapering or sharpened-edges 5| and These edges 51 and .52 enter a very small distance below the surface of the filter bed. Since the main object is to remove the scum or layer in the form of algae, amorphous matter, etc, resting upon the filter bed, but as such scum or layer may adhere to the topmost particles, the shoe enters below these topmost particles, entering a fraction of an inch below the level lia.

Assuming the movement of the surface cleaner 32 to be from left to right of Figure 4. as indicated by the arrow 53, then the superimposed layer of scum or the likeand the topmost particles of sand of the filter bed, if the filter bed be of sand, is forced into the channel 54,- and dueto the rotation of the fan member 55, having blades 56, in the direction ofthe arrow 51,.the

water with the impurities, and perhaps a-minor mains atits constant and desired level. The

water with its impurities, however, is siphoned through the orifice 53 into the pipe 33, .and is discharged into the wash water compartment II, as described in connection with Figure 8. The major part-of the sand passes over the shoe 50, and ispaddled by the blades 56 over the shoe 50 and descends on the downward slope 5|, as it ascended on the upward slope 52.

The surface cleaner 32 is suitably supported by providing the same with brackets 6| through which screw-threaded parts 62 of rods 98 pass, which extend upwardly to a movable platform 65, adjustment of such rods being possible through nuts 33, as alsoby screw-threads 31 and nuts 38.

The platform 85, shown best in Figures 1 to 3, is supported upon wheels 650a an axle 61, which wheels move upon rails 31a of the side tank walls 68 of the filter bed launder.

Upon the platform 65 there is also arranged an electric motor 63, the shaft 69 of which has a gear wheel I3 over which a drive chain 1| passes, which in turn passes over a gear or sprocket wheel 12 secured to a shaft I3 upon which the fan member 55 is secured, as shown in Figure 4. Thus. the rotation of the motor 68 causes arotation of the fan member 55. The motor shaft 69 has a second sprocket wheel 14 which moves a larger sprocket wheel I5 by means of a chain 16. The sprocket wheel I5 is keyed to the shaft 61, and moves the same. It will be seen, therefore, that the rotation of the motor in one direction rotates the fan member 55 in one direction and also moves the platform 65 in one direction.

After the platform 65 has reached one end of its travel on the rail 61a, it becomes necessary to reverse the action of the motor 68 and the rotation of the fan member 55 and the direction of movement of the'platform 55.

The pipe 33 ofFlgure 8 is provided at its lowermost end with a valve operating weighted member- -11 which at one end of the movement of the platform 65 strikes the rod 18, shown in Figure 1. This valve is shown in detail in Figure 5 where it is seen that the weighted member I1 is pivoted at 19 and has a valve member 80. When the valve member 33, with its depending portion ii, is in the vertical position shown in full lines, Figure 5, the channel 3| has a clear passage from the pipe 33 to the pipe 330., and the wash water descending-in pipe 33 can pass through the channel 8i into the pipe 33a. up to the T-member 3317 from which it is discharged from its orifice 34 into the launder l3. The extension of the pipe 33a indicated by 33 in Figure 1, is a pipe having no function excepting to balance the forces in supporting the valve device shown in Figure 5. If a pipe is used, it is capped, as shown by 84 in Figure 1. Instead of a pipe which is capped, a solid rod canbe used. The utilization of either a capped, hollow rod or a solid rod saves in material, since the valve device could be supported equally well by a stronger pipethan that indicated by pipe 33. As the platform 65 moves longitudinally over the filter bed with the surface cleaner 32 in action, the weighted member 11 takes the position as shown in full lines in Figure 5. When, however, the member 'l-l strikes the cross rod 18, then the member TI is thrown into the position as shown in dotted lines and indicated by 11a. The valve thencloses the channel 8| and prevents any further passage of fluid therethrongh. When the motor is reversed in its direction of rotation and thereby the platform is moved in the opposite direction, the rotation of the fan member 55 is--in opposite direction, and the weighted member "a being released falls back to its full line position as shown in Figure 1, and the fluid can pass through the channel 3| and be discharged out of the orifice 34 of the T-member 33b.

When the platform 65 reaches the extreme position at the other end of the filter bed, the member 11 will strike either against a small rod similar to the cross rod 13 at that end of the filter I6 as may be decided upon.

bed, not shown, or strike against a spray pipe 05 extending across the filter bed and in the path of the weighted arm '11, and thereby the member II is thrown into the position shown in dotted lines-and indicated by "b.

It will be noted from Figures 1, 2 and 3 that the water supply pipe It extends longitudinally along the filter bed-and is provided with upright branch pipes I9 arranged along the length of the filter bed having their orifices 20 at such level The water supply pipe ll'is'controlled by a hand operated valve 00, as shown in Figure 2, and is capped by a cap 81 at the other end of the filter bed, as shown in Figures 1 and 2.

Throughout the length of the-filter bed, the filtrate discharge pipes 3| are arranged, as shown in Figure 1, which conduct the filtrate into the filtrate launder I2.

In the pipe 33 as shown in Figure 3, a check valve 88 is shown which is preferably placed as close as possible to the surface cleaner 32. The position of the surface cleaner may be adjusted due'to the screw-threaded portion 01 of the supporting rods 96 and nuts 08. and correspondingly pipe 33 through a and 90, and part of the pipe 33,.the horizontal portion BI, is made of flexible metal hose so as to take care of the variations" in adjustment. A union joint I50 is provided therein to enable the hose to be separated. Extending upwardly of the T-jolnt' 92 of this flexible hose 9| and the depending pipe 33, there is a pipe 93 with a gate valve 94 having an open end 95. This open end 95 and the gate valve 04 are used for priming the operation when the apparatus is first set into operation'after standing idle, after which the valve 94 is closed and the siphoning efi'ect described is automatic.

The deep cleaner and sand replenisher are shown in the right hand side of Figures 1 and 2, as also in Figures 6 and 7. Referring particularly to Figure "I, it will be noted that the screen I supports the filter bed proper, I5, and that close to the surface of the screen I5 there are arranged two plow-like members I00, each pointing in an opposite direction. The plowlike member I00 is supported by vertical pipes IOI, which in turn supports a transverse or horizontal pipe I02. This pipe I02 has at its bottom a larger opening I03, and throughout its circumference a plurality of smaller openings I04. The pipes I 0| extend upwardly into larger pipes 40, and may be coupled thereto by suitable couplings I05. These pipes 40 extend vertically upward to the branch pipes 38 and receive water from the pump 31, as explained in connection with Figure 9, receiving air at the same time through the aspirator pipes 39.

Referring again to Figures 7 and 13, if the deep cleaner be moved from left to right in the direction of the arrow I09, the filter bed material will be caused to slide along the inclined surface I05, and become subjected to the action of water, or water and air, as shown in Figure 13. The space between the curved surface I05 and the plow I00 and the pipe I02 forms a channel I01, and is subjected to water and air jets and keeps the filter material from entering therethrough. As the filter bed particles fiow in the direction of the lines I10 (see Figure 13) and thus pass over the pipe I02, they are subjected to the sprays of cleaning water and air passing out of the pipe I02. Thereby, all the aggregated impurities of the filter bed particles are loosened and removed therefrom, and these ascend as shown by the arrows "I in Figure 13 upwardly through the filter bed with the water and air entraining the same, the air causing an upward ebullition, bounded by the 'outwardbub-' bles I12 (see Figure 13), and are captivated by a casing -IIO havinganopen bottom IIl,-and' ascendin this casing upwardly until they strike a plate H2, and in passing around this plate 'l I2 they are siphoned by the removal device 42 generally described in connection with Figure 10. This device, as shown in Figure 7,-consists of two longitudinal pipes 42a having openings 43 throughwhich the fluid with the impurities is' si phoned upwardly through the pipe through-its flexible connection 44a having a union joint toenable'separation thereof, and down through pipe 44 into the wash water launder I3;

Upwardly extending from the T-joint 44b of the flexible hose 44a is an upright pipe I'l5'having a gate valve H5 and an open orifice I", said open orifice and gate valve being used to prime the operation when the'apparatus is set into action. After it'has once been primed, the si phoning'action is automatic. I r

The pipes 40 may be vertically adjusted by means of the screw-threaded'portions H8 and .I t l a H?- The deep cleaner 35 and removal device 42 are supported by a plate -I55'ona platform I which, in turn, may be adjusted'by the-adjusting means I2I and I22 which cooperate with-the carriage frame 125 having a shaft I25,"wheels I21, and the rails 51a upon the tank wall 50. The carriage frame I25 has alsoa -motor I30. which, through the sprocket wheel -I 3 I'.- actuates by achain a sprocket wheel"-I32-and "in-turn rotates the shaft- I25, as seen in Figure, 1. This motor I has a bedplate I30a.which"rests upon this carriage frame I25. plate I30a also supports the pump 31 and its motor 314. as seen from Figures 1 and 11. Y

The deep cleaner can be readily removed from the casing IIO by simply unscrewing the union members I52 and I53, and then raising aplate I55, to which the pipes are attached. The adjustment of these pipes is carried out by the screw-threaded portions II8 of pipes "and nuts H9, and screw-threaded portion I and-nuts IGI of pipe 44. These adjustments in respect to the plate I are made also in respect to the position of the deep cleaner to the filter bed. By

this arrangement, the plate I55 can be removed by unloosening the union joints I52 and I53, and

the pipes 40 and 44 and deep cleaner as also the removing device, can be bodily removed from the remaining structure, under maintenance of the adjustments. When the deep cleaner is're turned in position, the adjustments having been retained, new adjustments are not necessary.

This plate I55 and correlated parts are shown in Figure 6 and in Figure 11.

Referring again to Figure 7, the plate H2 is Figures 1 and 2 and from Figures-6 and 7 that" the filter bed, through the action of the plow member I00 and the sprays of the pipe I02, cause a cleansing of the filter bed particles, and the wash water with its impurities is captured by the open ended casing H and siphoned out by the removal device 42 and discharged intothe launder I3 atthe'outlet 45 of the pipe 44.

At the lower end of pipe 44- and below-the outlet 45 there is provided a valve operating member of the same construction as described in connection with Figure 5, and this is operated by either striking a cross rod ltor the'spr'ay pipe 15, and as this has been fully described, repetition is not necessary. v 11 The pipe 44, is a structure substantially the duplicate of that described in connection with Figure 3, namely, pipe 33, has a duplicate blind pipe or rod for the purpose of adding strength to thestructure.

As the thorough agitation of theentire filter bed as described, and the force of-thewater'and air coming out of the pipe I02 together .with natural wear may cause certain particles of sand to be drawn upwardly with the impurities and be siphoned out by the removal device 42, it is proposed to combine with this deep cleaner, a sand replenisher. For this purpose, a sandbox 46 is provided which has openings 46a at its bottom and which holds sand, 46!). 'The bottom surface of the reticulated bottom is flush or level with the normally desired top surface of'the filter bed, but should the level of this filter bed be lowereddue to the abstraction of the sand through the removal device, orthrough wear, sandwill then" by gravity flow out-of the openings 46a and fill up the'gap and replenish the sand removed, and thereby restore the normally desired level of the filter bed. This sand container *46is shown clearly in Figure 1, and in section 'in Figure 2, and is also indicated diagrammatically in Figure 10.

Transversely of the filterv bed, and at one end thereof, is arranged a spray pipe'85 having opening HI and its end capped by the. cap I42 as shown in Figure 2, and in end view in Figure 1. The functionof this transverse pipe isto loosen the end part of the filter lied by'meansof water flow, when replacing the deep cleaner after its removal forrepair or inspection, at a'position immediately above the spray holes I. This pipe 85 is placed at one end of the filter bed," and may serve, as described, as an abutment to be impinged by the weighted depending member .11 'of the valve shown in Figure 6. -Whe'n=the deep cleaner has been removed and is again-replaced in the casing, it first rests on the top of thefllter bed. It cannot be forced down into position within the filter bed. It can, however, be brought into proper position, determined by its adjusting nuts I54 on the rods II by having the water of the spray pipe pass upwardly through the filter bed, whereby the. sand is loosened, and the deep cleaner can then sink down by its own weight.

There is also provided a flush pipe I44 having a manually operated valve I45 which serves to flush out the contents of the tank above the sand bed, should the same be desired. This pipe I44 is connected with an upright pipe I46 terminating-in an automatic float control device I41. The level in the tank operates through pipes I44 and I 46 the float control device I49; This, in turn, 'operates by a chain means I48, the starting switch of the motor-of the deep cleaner operating carriage. Thereby, the deep cleaner is operated by the head of the water in the tank; The head becomes larger as the filter bed itself needs cleaning.

From the foregoing, it will be seen that a new system of filtration has been provided. which system consists in providing a filtration bed and subjecting the same to periodic surface cleaning actions and periodic deep cleaning actions, with Y the replenishment'of sand or the like. A device for surface cleaning has been described which consists essentially in the removal from the filter bed of the topmost layer of the filter bed together with the impurities accumulated ther'ein, subjecting the same to agitating actionfor the separation of the impurities from the filter bed particles separating such filter-bed particles from the im- 'puritieameturning the-particles to the filter bed and siphoning ofi the water with the impurities. "The operatlon'just described is reversed in its direction at each end of the filter bed, and is oper- -ated-"on time intervals.

'-""Furthermore,the improved method of cleaning a" filter '-bedconsists in subjecting all parts thereof locally toagitation and displacement, and

while so displacing the particles, subjecting them to the action of an upward stream of water and air forremoving the impurities adhering to the i'i'artlcle's of the filter bed, and removing the wash water with the impurities from the local habitation of the agitation sphere, and should it be necessary,'supplyin'g the filter bed with a replenishment of sand or the like.

' 'I'heimprovement also consists in the special- 'structurescarrying out this method, in that a plow -shaped'oritapering member enters the bottom portion of the filter bed and subjects the portions of the-filter bed passing over such plow shaped device the impingement of streams of water, 'or' water and air, for removing impurities from the filter bed.

----liliioreo i'rer, an arrangement is provided to remove the pipe I 02 should it be necessary to re- --pair or replace, and such removal can be made longitudinally of the plow. Therefore, the novel principle proposed, as embodied in the invention herein described, is the of a fllter'bed of given thickness or depth and suitable length, having a filter medium such as sand, coal, magnetite, or like filter medium, operated upon by two cleaning apparatuses, first anapparatus to clean the top a fraction of an inch of the filter bed at frequent intervals, operating in time cycles as found necessary by test, depending upon the character of the material to be cleaned, and secondly, an apparatus to clean the entire body of sand or filter medium as is found to be necessary, depending again upon the character of the material to be cleaned and determin by the rise of head over the sand and governed by a float switch.

Reference hereinbefore has been made to the fact that all the drawings show the liquid levels aboutfthe same height, but the preferable form "is to have the level in the tank compartment higher than the level in the launders, whereby a greater head is obtained.

' In addition to the cleaning operation, it is important that the sand be kept at a predetermined depth. For this reason, the sand replenisher has been provided which replaces the sand which has been lost due to the cleaning action or natural wear.

With each cleaning apparatus, whether surface cleaning or-deep cleaning, an off-take by siphoning of the dirty water is provided, with control valves, and a new deep cleaner provision has been made for the wash water to wash the sand by a pump, for instance; this wash water drawing-with it air through aspirator pipes to assist in the washing.

For tanks with one hundred running feet of filter bed or less, one surface and one deep cleanfer would besufilcient, but on longer tanks, twosurface cleaners with one deep cleaner-would be provided, with the deep cleaner disposed-between the surface cleaners,

bed to the centre :thereof, and basic-whereas the .deep cleaner would make an entire cleaning cycle, t

a lever controlling a mercoid switch, which vin turn controls starting and stopping of the carriage motor, this in order to prevent the carriage movement in the event that the wash water pump is inoperative.

agitating action,

Suitable controls, wtih starting and reversing switches for the operation of the motors and the carriages, areprovided, but as these form no part of the invention, they have not been shown nor described in detail.

While I have illustrated and described the preferred form of construction for carrying. my invention into eifect, this is capable of variation and modification without departing ,,from the spirit of thefinvention. I, therefore, do not wish to be limited to the precise details of construction set forth, butdesire to avail myself of such variations, modifications and adaptations as come within the scope of the appended claims.

What I claim is: v v

1. In a filtration system, a surface cleaner comprising-fa be resting on the upper portion of the filter bed, a blade wheel adjacent. said shoe, and a housing for said blade wheel, open at the lower side thereof and having an outlet at its upper end, whereby the uppermost' layer of the filter bed with its impurities is subjected to with the impurities passing out of -the outlet and the filter bed materal returning to the filter bed.

2. In a filtration system, a surface cleaner comprising a shoe having tapered portions, the bottom being horizontal, and the sides inclined thereto,'in opposite directions, each adapted to enter the filter bed close to its normal upper level, depending on the direction of movement of the surface cleaner, means disposed adjacent said shoe and between the two tapered portions, for moving the water with impurities away from the filter bed, and means for removing said water with impurities from said last named means.

3. In afiltration system, a surface cleaner comprising a shoe of tapering shape adapted to enter the filter b ed close to its normal upper level .to form a layer of filter bed material over the shoe, a blade wheel adjacent said shoe for agitating the water with impurities in said layer moved by the shoe away from the body of the filter bed, and means as; removing said water with impurities from said blade wheel.

4. In a filtration system, having a filter bed, the combination of a surface cleaner comprising a shoe having a horizontal bottom surface and another surface inclined thereto, the tapering ends thereof being adapted to enter immediately below the top surface of the filter bed and separate a layer of filter bed, means adjacent said shoe for removing the impurities with entrained water from said separated top surface layer,

means formed of a bottom surface and an inclined surface forming a tapering end for returning the layer to the filter body, said shoe extendin which case the surface 1 cleaners would run onlyfrom the end of the filter =ing across the filter-bed, and means for moving the shoeEalong the surface of the filter bed.

5. In a filtration system, having a filter bed. the combination in a top surface cleaner of a wedge resting upon the upper portion of the filter 5 bed to separate the uppermost layer from the 'filter bed, a housing having an outlet to remove from the separated layer the impurities thereof and the water entraining the same, and ablade. wheel within the housing for directing theiml0 purities to the outlet of the housing and returning the layer to the body of the filter bed, after being separated from the impurities.

6. In a filtration system, having a filter bed on a sieve, a deep cleaner comprising a shoe having a bottom surface horizontally disposed and a surface upwardly inclined thereto, the tapered edge being adapted to enter the filter bed and to engage the lower portion of the filter bed adjacent the sieve, and means adjacent and at the 20 rear of said shoe forsubjecting the portions of .the filter bed passing over the shoe, when the shoe moves through the filter bed, to the action of fiuid jets, said means being spaced from :the shoe to permit the filter bed material to pass therebetween.

7. In a filtration system, a deep cleaner comprisinga shoe having a bottom surface horizontally disposed and a surface upwardly inclined thereto, the tapered edge being adapted to enter the filter bed and to engage the lower portion of the filter bed adjacent the sieve,.means adjacent and at the rear of said shoe and adjacent the sieve for subjecting the portions of the filter bed 35 passing over the shoe and the sieve, when the shoe moves through the filter bed, to the action of fluid jets, and means for removing the wash water with the impurities from the system.

8. In a filtration system, having a' filter bed and a sieve, a deep cleaner comprising a horizontal pipe engaging the lower portion of the filter bed close to the sieve, said pipe having perforations, a wedge shaped member spaced from said horizontal pipe permitting a space between 45 the member and horizontal pipe, vertical means extending upward through the entire depth of the filter bed, and means supplying the vertical means with a fluid, whereby the filter bed directed by the wedge shaped member into said 50 space is acted upon by the fluid passingthrough the perforations of the horizontal pipe, and the fluid passing through other perforations of the horizontal pipe directs the impurities upwardly.

9. In a filtration system, a filter bed replenisher, consisting of a casing substantially the width of the filter bed for holding filter bed material, and having a plurality of openings in its bottom for releasing said material from said so casing, and means for moving said casing along and upon the upper surface of the filter bed to compensate any variations in the normal level of the filter bed, said bottom of the casing being flush with the surface of the normal level of the 66 filter bed. a

10. In a filtration system, the combination of a tank having a filter bed, the combination of a surface cleaner having means to remove the top layer of the filter bed, means moving the surface 70 cleaner along the top surface only of the filter bed at certain periods, a deep cleaner having means extending through the body of the filter bed close to the sieve and movable through the body of the filter bed and along the sieve, and II amuse means for moving the deep cleaner at other periods in the filter bed tank.

11. In a filtration system having a filter bed tank, and a launder, the combination of siphoning means for guiding water from said tank to said launder, a control valve in said means disposed in the launder for opening or closing the siphoning means, means for moving the siphoning means from one end of the filter bed to the other, a weighted member for operating said valve and-extending therefrom, and stationary means in the path of movement of said control valve in said launder for opening the weighted member of the valve, said means being at least one end of the tank.

12. In a filtration system, the combination of a tank, a filter bed therein, a deep cleaner vertically movable through said filter bed, a stationary perforated pipe transversely across said filter bed at the lowermost portion thereof, and means supplying fluid to said pipe and through said perforations for subjecting the filter material above the stationary pipe to an ebulliency to permit the deep cleaner seated upon the'surtace or the filter bed to descend by'gravity through the ebullient filter material above said perforated pipe.

13. In a filtration system having a filter medium body and a water layer thereover, a surface cleaner comprising-a shoe with horizontal bottom section and concave upper section, said shoe being adapted to be set in the filter medium at a predetermined depth near the upper surface thereor, means for moving said shoe forward and over the filter bed at said depth for passing a layer of filter medium with its entrained water oversold shoe, means adjacent said shoe for agitating said separated filter medium to separate the dirty ma- ,terial from the filter medium, means'for immediately returning to the filter medium body the, separated filter medium tosubstantiallyits origisystem waterwiththe dirtyi'mate'rial sep t ted so from said separated filter medium; ,l 

